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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - DC DC Switching Regulators

onsemi FAN53730UC02X

Name: FAN53730UC02X
Brand: onsemi
SKU: FAN53730UC02X
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FAN53730UC02X

Manufacturer:: onsemi

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 12-XFBGA, WLCSP

Datasheet:: FAN53730UC02X.pdf

Description:: IC REG BUCK PROG 3A 12WLCSP

Quantity:: RFQ Add To RFQ list

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Product details

Overview

FAN53730UC02X from onsemi is an I²C-controlled 3 A synchronous buck regulator with Constant On-Time (COT) topology, supporting 2.3 V–5.5 V input and programmable 0.3 V–2.0 V output. It delivers fast transient response, 2.5 MHz CCM switching, forced CCM mode, audio reduction, and power-good signaling-designed for LPDDR memory power rails in mobile SoCs.

For engineers reviewing the FAN53730UC02X datasheet, pinout, applications, or equivalent options, key selection criteria include I²C programmability of VSET1/VSET2 (1.00 V / 1.05 V), 12.8 µA quiescent current in DCM, thermal/UVLO/fault protection, and WLCSP12 package compatibility with high-density mobile PCB layouts.

Technical Context

The FAN53730UC02X implements a variable-frequency COT control architecture that dynamically adjusts switching frequency based on load to optimize efficiency-operating in discontinuous conduction mode (DCM) at light loads and transitioning to ~2.5 MHz continuous conduction mode (CCM) above ~1 A. Its valley-current-limited power stage supports up to 3 A output with programmable 4.6 A / 2.3 A current limit thresholds via I²C register VAL_ILIM.

I²C interface (Fast Mode Plus, 1 MHz max) enables full configuration: dynamic voltage scaling (DVS) with 8 slew rates, audio reduction mode (ARM) with 25 µs / 40 µs timeout, PG polarity inversion, and output discharge disable-all without requiring external logic. The device integrates internal high-side (33 mΩ) and low-side (23 mΩ) MOSFETs and operates across −40°C to +85°C ambient.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	2.3 V to 5.5 V - supports single-cell Li-ion, USB PD, and PMIC intermediate bus rails without external LDO pre-regulation.
Output Voltage Range	0.3 V to 2.0 V - programmable in 10 mV steps via I²C; default VSET1/VSET2 = 1.00 V / 1.05 V for LPDDR4/LPDDR5 core voltage sequencing.
Max Output Current	3 A - verified under 2.5 V–5.5 V input and 0.3 V–1.0 V output per derating curve (Fig. 33), limited by thermal and valley-current constraints.
Quiescent Current	12.8 µA (DCM, no load) - enables >100-hour battery standby in always-on mobile subsystems with minimal leakage impact.
Switching Frequency	~2.5 MHz in FCCM - reduces external component size (0.24 µH inductor, 2×22 µF 0402 output caps) and avoids AM radio band interference.
I²C Interface	Fast Mode Plus (1 MHz), 7-bit address 0x20 (0x22 for UC02X) - allows multi-device addressing and register-level control of DVS, ARM, PG_POL, and fault behavior.
Protection Features	UVLO (2.3 V rising), thermal shutdown (150°C), short-circuit timeout (40 µs), overcurrent (valley-limited), and PG monitoring - eliminates need for discrete fault management circuitry.

Pinout & Package

Package: 12-bump WLCSP (1.07 mm × 1.36 mm, 0.35 mm pitch, Case 567GK), bottom-side solder bumps, designed for ultra-compact mobile PCBs with minimal board area and thermal resistance (θ_JA = 130°C/W on 2s2p).

Pin/Terminal	Circuit Role	Design Meaning
A1 SDA/FCCM	I²C data line / FCCM enable	Bi-directional SDA in I²C mode; pull-high to force CCM when used as FCCM control-enables seamless transition between efficiency-optimized DCM and noise-sensitive CCM operation.
A2, A3 IN	Main power input	Dual-bump VIN connection lowers IR drop and improves current sharing-supports up to 5.5 V input with integrated UVLO hysteresis (100 mV).
B1 SCL	I²C clock input	Dedicated clock input for synchronized register access; must be pulled to GND in logic-controlled variants but actively driven here for full configurability.
B2, B3 SW	Switching node	High-current path to external inductor; requires tight layout with low-inductance routing to minimize EMI and voltage spikes during 33 mΩ/23 mΩ FET transitions.
C1 VSEL	Voltage select input	Logic-level input selecting between two I²C-programmed output voltages (VSET1/VSET2); enables dual-rail sequencing without additional GPIOs.
C2, C3 GND	Power ground	Dual GND bumps provide low-impedance return path for both power and signal currents-critical for stable COT regulation and PG accuracy.
D1 PG	Power good open-drain output	Asserts when VOUT ≥ 93% of target and ramp complete; polarity programmable via Reg 03h[0]-synchronizes SoC boot sequence and enables system-level fault detection.
D2 EN	Enable input	Active-high logic enable; device remains I²C-accessible in shutdown (EN = low) for status reads-supports controlled power-down without bus reset.
D3 OUT	Output voltage sense	Direct connection to output capacitor positive terminal; enables accurate remote sensing and compensates for PCB trace IR drop in high-current paths.

Key Features

Feature	Design Value
Constant On-Time (COT) Control	Delivers <10 µs load transient recovery (Fig. 16–17) without external compensation-ideal for burst-mode CPU/GPU voltage scaling in mobile APs.
Audio Reduction Mode (ARM)	Eliminates audible ceramic capacitor whine by forcing minimum 25 kHz/40 kHz switching via programmable dead-time timeout-critical for smartphone camera and display modules.
Dynamic Voltage Scaling (DVS)	Programmable 2–16 s/10 mV step enables controlled SoC core voltage ramping during DVFS transitions-reduces inrush current and prevents brown-out during frequency changes.
Forced Continuous Conduction (FCCM)	Enables fixed-frequency operation via I²C or SDA/FCCM pin-suppresses frequency modulation noise in RF-sensitive bands (e.g., near LTE/WiFi front-end modules).
Integrated Power Good (PG)	Configurable active-high/active-low open-drain output with 128 µs deglitch-provides deterministic SoC reset timing and eliminates need for external supervisor ICs.

Applications

LPDDR Memory Power	Mobile Application Processor Core Rail
Use Scenario: Supplying VDDQ/VDD2 for LPDDR4X/5 DRAM in smartphones and tablets with strict 0.3–1.1 V tolerance and fast dI/dt demands. IC Role / Device Role / Timing Role: Primary buck regulator delivering up to 3 A with <10 µs transient response and I²C-configurable VSET1/VSET2 for memory initialization and self-refresh modes. Use Value: Enables direct DRAM rail regulation without intermediate LDOs-reducing BOM count, board space, and power loss while meeting JEDEC AC timing margins.	Use Scenario: Powering CPU/GPU cores in application processors (e.g., Qualcomm Snapdragon, MediaTek Dimensity) requiring dynamic voltage scaling during performance state transitions. IC Role / Device Role / Timing Role: Programmable buck converter executing DVS ramps with 10 mV/step resolution and 2–16 s/step timing-synchronized to SoC DVFS controller via I²C. Use Value: Prevents system brown-out during rapid voltage transitions and eliminates need for external DACs or sequencers-simplifying power architecture and improving reliability.
RF Front-End Module Bias	Always-On Sensor Subsystem
Use Scenario: Generating clean, low-noise 1.0 V–1.8 V bias for LTE/WiFi RF transceivers and power amplifiers where switching noise can degrade EVM and ACLR. IC Role / Device Role / Timing Role: FCCM-enabled buck operating at fixed 2.5 MHz to avoid sensitive RF bands; ARM disabled to prioritize efficiency over acoustic noise. Use Value: Achieves <6 mVpp ripple (CCM) and >89% efficiency at 1 A-meeting RF module PSRR requirements without adding ferrite beads or LC filters.	Use Scenario: Powering always-on motion sensors, ambient light sensors, and secure enclaves in wearables and IoT edge devices requiring multi-day battery life. IC Role / Device Role / Timing Role: Ultra-low-I_Q buck (12.8 µA) in DCM mode with automatic PFM entry below 2 mA-maintaining regulation while minimizing quiescent drain. Use Value: Extends coin-cell or small Li-ion battery runtime by >30% versus fixed-frequency alternatives-enabling 12+ months of operation in maintenance-free deployments.

LPDDR Memory Power

Mobile Application Processor Core Rail

Use Scenario: Supplying VDDQ/VDD2 for LPDDR4X/5 DRAM in smartphones and tablets with strict 0.3–1.1 V tolerance and fast dI/dt demands.

IC Role / Device Role / Timing Role: Primary buck regulator delivering up to 3 A with <10 µs transient response and I²C-configurable VSET1/VSET2 for memory initialization and self-refresh modes.

Use Value: Enables direct DRAM rail regulation without intermediate LDOs-reducing BOM count, board space, and power loss while meeting JEDEC AC timing margins.

Use Scenario: Powering CPU/GPU cores in application processors (e.g., Qualcomm Snapdragon, MediaTek Dimensity) requiring dynamic voltage scaling during performance state transitions.

IC Role / Device Role / Timing Role: Programmable buck converter executing DVS ramps with 10 mV/step resolution and 2–16 s/step timing-synchronized to SoC DVFS controller via I²C.

Use Value: Prevents system brown-out during rapid voltage transitions and eliminates need for external DACs or sequencers-simplifying power architecture and improving reliability.

RF Front-End Module Bias

Always-On Sensor Subsystem

Use Scenario: Generating clean, low-noise 1.0 V–1.8 V bias for LTE/WiFi RF transceivers and power amplifiers where switching noise can degrade EVM and ACLR.

IC Role / Device Role / Timing Role: FCCM-enabled buck operating at fixed 2.5 MHz to avoid sensitive RF bands; ARM disabled to prioritize efficiency over acoustic noise.

Use Value: Achieves <6 mVpp ripple (CCM) and >89% efficiency at 1 A-meeting RF module PSRR requirements without adding ferrite beads or LC filters.

Use Scenario: Powering always-on motion sensors, ambient light sensors, and secure enclaves in wearables and IoT edge devices requiring multi-day battery life.

IC Role / Device Role / Timing Role: Ultra-low-I_Q buck (12.8 µA) in DCM mode with automatic PFM entry below 2 mA-maintaining regulation while minimizing quiescent drain.

Use Value: Extends coin-cell or small Li-ion battery runtime by >30% versus fixed-frequency alternatives-enabling 12+ months of operation in maintenance-free deployments.

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TPS62864DRLR	4 A rating, 1.8 V–5.5 V input, 0.4–1.95 V output; pin-compatible WLCSP but lacks I²C-uses hardware VSEL pins only.	Fixed dual-VOUT option only; no DVS, ARM, or PG polarity control-suitable for cost-sensitive designs without dynamic sequencing needs.	Select when I²C configurability is unnecessary and higher current headroom is required; verify thermal margin at 4 A in same PCB layout.
RTQ2132BWGE	3 A, I²C-programmable, 2.3–5.5 V input, 0.5–1.52 V output; QFN-12 package (2 mm × 2 mm) with exposed thermal pad-higher θ_JA (65°C/W) than WLCSP.	Supports similar DVS/ARM features but requires larger board area and reflow profile optimization for thermal pad; no VSEL pin-full I²C dependency.	Select when thermal design permits QFN and board space allows larger footprint; preferred for industrial temperature range (−40°C to +125°C) support.

Compared with TPS62864DRLR and RTQ2132BWGE, the FAN53730UC02X uniquely combines WLCSP12 miniaturization, I²C-based dual-VSET flexibility, and ARM-enabled silent operation-making it optimal for space-constrained, acoustically sensitive mobile memory and processor rails where programmability and footprint are critical.

Availability

FAN53730UC02X is available at Aetrix Electronics and suitable for LPDDR memory power, mobile application processor core rails, RF front-end bias, always-on sensor subsystems, and portable medical device power management requiring stable component supply and long-term lifecycle assurance.

Supply support for FAN53730UC02X includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi is a global semiconductor leader focused on energy-efficient innovation, delivering silicon solutions for automotive, industrial, cloud, and mobile end-markets with emphasis on high-reliability analog and power management ICs.

The FAN53730UC02X belongs to onsemi's high-efficiency mobile power management portfolio, engineered specifically for ultra-thin smartphones, wearables, and edge AI devices demanding sub-millimeter footprint, I²C configurability, and acoustic-noise-free operation.

FAQ

What is the I²C address of the FAN53730UC02X?

The FAN53730UC02X uses a 7-bit I²C address of 0x22 (hex), as specified in the Ordering Information table on page 2 of the datasheet. This differs from the base FAN53730UCX variant (0x20) to allow coexistence of multiple FAN53730 devices on the same bus. The address is hardwired and not software-configurable; all register reads/writes for the FAN53730UC02X must target 0x22.

Does the FAN53730UC02X support Dynamic Voltage Scaling (DVS)?

Yes, the FAN53730UC02X fully supports DVS via I²C registers. Using RR_DVS bits (Reg 02h[4:2]), the output voltage slew rate is programmable from immediate step-change to 16 seconds per 10 mV increment. DVS is enabled by setting DVS_EN (Reg 06h[4]) = 1. The FAN53730UC02X executes precise voltage transitions between its I²C-programmed VSET1 (1.00 V) and VSET2 (1.05 V) targets-critical for SoC DVFS compliance.

How does the Audio Reduction Mode (ARM) function in the FAN53730UC02X?

The FAN53730UC02X implements ARM by monitoring DCM idle time and forcing a switching cycle if the dead time exceeds a programmable threshold (25 µs or 40 µs, set via ARM_TO in Reg 02h[6]). When ARM_EN (Reg 06h[5]) = 1, this ensures minimum switching frequencies of 40 kHz or 25 kHz-eliminating audible noise from ceramic capacitors. ARM is exclusive to I²C-controlled variants like the FAN53730UC02X and cannot be enabled on logic-controlled versions.

What is the maximum output current capability of the FAN53730UC02X?

The FAN53730UC02X delivers up to 3 A DC output current, validated per the Typical Derating Curve (Fig. 33) across 2.5 V–5.5 V input and 0.3 V–1.0 V output at +85°C ambient. This limit arises from thermal constraints and valley-current limiting (IVALLEY = 4.6 A typ). At 3 A, efficiency reaches ~83% (VIN = 3.8 V, VOUT = 1.0 V); sustained 3 A operation requires adequate PCB copper area and thermal vias per the 2s2p layout guidelines in the datasheet.

Can the power-good (PG) output polarity be changed on the FAN53730UC02X?

Yes, the PG polarity is fully configurable via the PG_POL bit (Reg 03h[0]) in the FAN53730UC02X. By default, PG is active-high open-drain (pulls low when inactive). Setting PG_POL = 0 configures PG to active-low-pulling low when VOUT is in regulation. This flexibility allows direct interfacing with SoC reset inputs or FPGA configuration logic without external inverters, and is unique to I²C-controlled variants like the FAN53730UC02X.

FAN53730UC02X Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: 12-XFBGA, WLCSP

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Programmable

Number of Outputs:: 1

Voltage - Input (Min):: 2.3V

Voltage - Input (Max):: 5.5V

Voltage - Output (Min/Fixed):: 0.3V

Voltage - Output (Max):: 2V

Current - Output:: 3A

Frequency - Switching:: 2.5MHz

Synchronous Rectifier:: Yes

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 12-WLCSP (1.07x1.36)

FAN53730UC02X FAQ

1.How can I place an order for FAN53730UC02X through Aetrix?

Please submit a Request for Quotation (RFQ) for FAN53730UC02X on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for FAN53730UC02X reliable?

The price and inventory of FAN53730UC02X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN53730UC02X is usually 5 days.

3.What payment methods are accepted for FAN53730UC02X?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN53730UC02X transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FAN53730UC02X?

FAN53730UC02X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FAN53730UC02X order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for FAN53730UC02X?

For technical support, including FAN53730UC02X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN53730UC02X requirements.

6.How does Aetrix verify that FAN53730UC02X is sourced from the original manufacturer or authorized distributors?

All FAN53730UC02X products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that FAN53730UC02X meets industry standards.

7.What is the process for return or replacement of FAN53730UC02X?

All FAN53730UC02X units undergo pre-shipment inspection (PSI). If there is an issue with FAN53730UC02X, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The FAN53730UC02X part is unused and in its original packaging.

Return procedure for FAN53730UC02X:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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